Patch "can: fix loss of CAN frames in raw_rcv" has been added to the 4.1-stable tree

This is a note to let you know that I've just added the patch titled

can: fix loss of CAN frames in raw_rcv

to the 4.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
can-fix-loss-of-can-frames-in-raw_rcv.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Oliver Hartkopp <[email protected]>
Date: Sun, 21 Jun 2015 18:50:44 +0200
Subject: can: fix loss of CAN frames in raw_rcv

From: Oliver Hartkopp <[email protected]>

commit 36c01245eb8046c16eee6431e7dbfbb302635fa8 upstream.

As reported by Manfred Schlaegl here

http://marc.info/?l=linux-netdev&m=143482089824232&w=2

commit 514ac99c64b "can: fix multiple delivery of a single CAN frame for overlapping CAN filters" requires the skb->tstamp to be set to check for identical CAN skbs.

As net timestamping is influenced by several players (netstamp_needed and netdev_tstamp_prequeue) Manfred missed a proper timestamp which leads to CAN frame loss.

As skb timestamping became now mandatory for CAN related skbs this patch makes sure that received CAN skbs always have a proper timestamp set. Maybe there's a better solution in the future but this patch fixes the CAN frame loss so far.

---
 drivers/net/can/dev.c   |    5 +++++
 drivers/net/can/slcan.c |    1 +
 drivers/net/can/vcan.c  |    3 +++
 net/can/af_can.c        |    6 +++++-
 4 files changed, 14 insertions(+), 1 deletion(-)

@@ -440,6 +440,9 @@ unsigned int can_get_echo_skb(struct net
 		struct can_frame *cf = (struct can_frame *)skb->data;
 		u8 dlc = cf->can_dlc;
 
+		if (!(skb->tstamp.tv64))
+			__net_timestamp(skb);
+
 		netif_rx(priv->echo_skb[idx]);
 		priv->echo_skb[idx] = NULL;
 

@@ -575,6 +578,7 @@ struct sk_buff *alloc_can_skb(struct net
 	if (unlikely(!skb))
 		return NULL;
 
+	__net_timestamp(skb);
 	skb->protocol = htons(ETH_P_CAN);
 	skb->pkt_type = PACKET_BROADCAST;
 	skb->ip_summed = CHECKSUM_UNNECESSARY;

@@ -603,6 +607,7 @@ struct sk_buff *alloc_canfd_skb(struct n
 	if (unlikely(!skb))
 		return NULL;
 
+	__net_timestamp(skb);
 	skb->protocol = htons(ETH_P_CANFD);
 	skb->pkt_type = PACKET_BROADCAST;
 	skb->ip_summed = CHECKSUM_UNNECESSARY;

@@ -207,6 +207,7 @@ static void slc_bump(struct slcan *sl)
 	if (!skb)
 		return;
 
+	__net_timestamp(skb);
 	skb->dev = sl->dev;
 	skb->protocol = htons(ETH_P_CAN);
 	skb->pkt_type = PACKET_BROADCAST;

@@ -78,6 +78,9 @@ static void vcan_rx(struct sk_buff *skb,
 	skb->dev       = dev;
 	skb->ip_summed = CHECKSUM_UNNECESSARY;
 
+	if (!(skb->tstamp.tv64))
+		__net_timestamp(skb);
+
 	netif_rx_ni(skb);
 }
 

@@ -310,8 +310,12 @@ int can_send(struct sk_buff *skb, int lo
 		return err;
 	}
 
-	if (newskb)
+	if (newskb) {
+		if (!(newskb->tstamp.tv64))
+			__net_timestamp(newskb);
+
 		netif_rx_ni(newskb);
+	}
 
 	/* update statistics */
 	can_stats.tx_frames++;

Patches currently in stable-queue which might be from [email protected] are

queue-4.1/can-fix-loss-of-can-frames-in-raw_rcv.patch